A frameless window is a window in which the pane is not surrounded by a frame for at least a significant part of the time during normal use. One example which is particularly relevant is that of a frameless window for a door of a motor vehicle, especially the front door of a sports car such as a coupe, convertible or other vehicle lacking a B pillar. A B pillar is the bodywork member which separates the front windows from the rear windows of a vehicle. In a vehicle door having a frameless window, no window frame is provided in the door itself, so when the door is open, the pane extends upwards from the door without lateral support. However, when the door is shut, the pane is received against seals in the vehicle bodywork, and is normally surrounded by such bodywork, and to that extent the window may not be regarded as entirely frameless.
It will be appreciated that, given the lack of lateral support for the pane, it is important to achieve precise positioning of the pane relative to the door, so that the pane comes into sealing contact with the bodywork seals when the door is shut. The lower edge of the pane is held in members known as holders, which generally have a U-shaped configuration, and may be bonded to the pane.
WO 01/98613 discloses a process and an apparatus for manufacturing frameless windows which comprise a glass pane, the lower edge of which is fixed by means of adhesives in the slot of one or more holders. These windows, already provided with said holders, are arranged onto a work-table in a substantially horizontal position. A portion of these holders is removed when the windows lie on the work-table, so as to compensate the shape variations of the glass pane with respect to its nominal shape. These shape variations can also be compensated by slightly modifying the mutual position of the pane with respect to the holders by exploiting the minimum gap which is comprised in the slot between the pane and the holders for applying the adhesives between them.
Similar windows and manufacturing arrangements are also disclosed in DE 4340363, FR 2762350 and WO 2004/016894.
However, in all the above mentioned known windows, the possibility of compensating the shape variations of the glass pane is very low since the high precision and the short manufacturing times required for mounting the window do not allow to employ holders with relatively wide slots.